Hi people.For my ingame user interface I have implemented a textured object, that acts like button, has onMouseOver(), onClicked() , events etc.Right now for every single object of that type, I have a property for the page it belongs. I.e. the Main menu widgets have page property set to 0, the Options widgets have their page propery set to 1 etc. Then, when the user press for example hit "escape" I set the page number to 0 and draw the widgets that have page property set to 0, when the user click on Options I set the page index to 1 and draw widgets that have page 1 etc..This works but I have a feeling that it isn't flexible and could cause a lot of interating over the widgets list to draw only the elements that match the current page.I think there might be better practices to implement GUI systems. For example, make separate list of widgets fort every page. Something likeGUISystem{std::vector<Widget*> mainPage ;std::vector<Widget*> options ;}

and then interate the appropriate list and draw elements.

Is there other better approaches ? How do you guys will implement such a GUI system ?

"myGUI" has all state of the art features you expect from a GUI. why re-write everythin from zero? You have just to provide drawing functions, all other logic is handled for you.

write a good GUI system is almost hard as writing a good 3D engine. untill you need a button and some text is feasible, but more complex stuff will get harder and harder

anyway a system like your should be a list of lists. So only one list is active at a time. Unless you are going to have hundreds elements for each list, iterating every element is not very heavy operation.

Then if you are going to have many elements, probably is better to also have a "I Am Here" index so that iteration starts from the first visible element instead from the begin of the list. (also using a grid is very nice so that screen is divided into quads and each element is indexed by (X,Y) instead of by (IDX).

(by the way, the active list is already a "I Am On This List" stuff)

Edited by DemonRad, 07 July 2012 - 04:39 AM.

Peace and love, now I understand really what it means! Guardian Angels exist! Thanks!

Instead of having a list of widgets, I used a tree structure. I.e. each object is a node, and has a parent, and can have children. The implementation I wrote is fairly similar to a 'scene graph' which is often used in 3d engines / 3d modelling tools.

If you use this 'parent child' relationship you can make coordinates relative, and have the position of widgets / objects relative to their parent. So when you move e.g. a dialog box all it's child controls also move automagically.

You can also easily 'cull' off branches of the scene graph just by setting a cull flag on a branch, and recursive updates / renders etc will go no further, and update / render only bits that you have changed (instead of trying to render the whole GUI each frame).

DemonRad, I don't know what's wrong with me, but I prefer make things myself. myGUI looks nice, but I prefer more C-like code style. myGUI looks heavy Ogre influenced at first glance.

lawnjelly - thanks. My GUI currently isn't very complex, so simple textured alphatested, blended object with mouse events are sufficient, moreover I plan to use a game launcher that will implement using operating system controls most of the graphics, sounds options, sliders etc. A hierarchy you descibed is easily implemented and I consider making the step in that direction when the time comes.

Instead of having a list of widgets, I used a tree structure. I.e. each object is a node, and has a parent, and can have children. The implementation I wrote is fairly similar to a 'scene graph' which is often used in 3d engines / 3d modelling tools.

If you use this 'parent child' relationship you can make coordinates relative, and have the position of widgets / objects relative to their parent. So when you move e.g. a dialog box all it's child controls also move automagically.

You can also easily 'cull' off branches of the scene graph just by setting a cull flag on a branch, and recursive updates / renders etc will go no further, and update / render only bits that you have changed (instead of trying to render the whole GUI each frame).

write a good GUI system is almost hard as writing a good 3D engine

Not in my experience.

When you have to support several different econdings, and gui serialization with a decent GUI editor yes ;-). I prefer too do things myself. Anyway if you already done scene graph stuff, half of the work is done for the GUI.

Peace and love, now I understand really what it means! Guardian Angels exist! Thanks!